I appreciate the immense combined knowledge offered by the members of thIs board. PRS bedazzle wannabe luthiers like myself with their 'new' takes on electric instruments but I have been reading today about their endeavours in the acoustic world. As I intend this to be a topic of discussion and not a specific question about or thread regarding my individual forays into acoustic luthiery I have decided to post this here.

Mr. Smith hisself appears on some YouTube videos outlining the concepts and ideas behind the construction of his acoustic line. He begins by saying that his shop has their collective hands on a Torres and has had the opportunity to x-ray it. They came to the conclusion that the soundbox was constructed more like a speaker cabinet and that the back and sides were ultimately as rigid as possible in order to reflect all of the sound back out, making the soundboard and strings act 'as one' to use his phrase, in order to produce an even powerful instrument with good base response. PRS feel that they have taken lessons from this and bucked the trend so to speak through their design process where they make the back and sides as rigid as possible, even using mahogany braces on the backplate. The neck contains one very substantial lump of graphite in place of a truss rod to mimic the steel reinforced necks of 'those early martins and other guitars so beloved to the keepers of the mojo' to paraphrase.

So my question to you is what do you think of all of this? Is all of this an avenue worth pursuing over and above producing a more stereotypical American style steel string guitar like those described in the pages of Cumpiano etc...?

Has anyone here tried one of these and do you believe tht there is a mojo in this non-standard construction techniques or are you experimenting in this manner yourself?

There are a lot of builders out there, and they all have differing ideas on this. PRS is not the first guy to do "stiff and solid" back and sides approach. Some use double sides and really big and stiff linings, and PRS seems to be in the "solid non-moving back" camp as well. It sounds like he wants all of the vibration and string energy to be at the top and no where else. In my opinion this is nothing new. most of his experience is in electric guitars and frankly there are a lot of other builders who have studied this a lot more than he has.

Absolutely Mark; let's not forget that they feel they have learned their lessons from this Torres they xrayed. He demonstrates that so much of the response comes from the soundboard he places his arm across it to dampen the sound and it's audible even on the low quality videos.

I could be wrong, but didn't Torres build classical guitars? I guess it's reasonable to examine the construction to obtain some insight, but it seems to me that steel string guitars and classical guitars are not similiar enough in their design parameters to be able to get much useful information about building steel strings from examining a classical, even if it's the very best classical ever constructed.

A man hears what he wants to hear, and disreguards the rest. Paul Simon

Rodger Knox wrote:I could be wrong, but didn't Torres build classical guitars? I guess it's reasonable to examine the construction to obtain some insight, but it seems to me that steel string guitars and classical guitars are not similiar enough in their design parameters to be able to get much useful information about building steel strings from examining a classical, even if it's the very best classical ever constructed.

You're right Rodger, but these PRS' even have fanned bracing albeit augmented and encorporated into an x brace system. My understanding is that the origin of the different construction of the steel string acoustic was by no small part in dealing with the higher tension of the strings and therefore a more robust bracing structure evolved. It seems that they may not be trying to reinvent the wheel but are doing something more a kin to looking at the design aspects of great carriages when designing a modern automobile.

Apart from lookng at a Torres guitar, I guess they may have even invested in copies of the Erwin Somogy books and the Gore and Gilet books. Read those four volumes and study Gore and Gilet mathematical model about degrees of freedom (of movement in back and sides) and know more than you ever imagined possible about thick/thin/rigid/flexible/heavy/light/etc etc back sides and tops.

Both sets really good for anyone interested in learning more about the craft.

Thanks for the input guys, this is exactly what I wanted to see Care to elaborate at all Barry? are you saying it's all hogwash? nothing but ad men spin? Seems that it's aimed at a particularly well informed customer if that is the case!

Thanks very much for the reading list Simon! I have no doubt that a company like PRS spent an enormous amount of time and money on R&D before leaping into a new marketplace. After all; they are a relative newcomer and share the upper echelons of the corporate ladder with the big old mammoths who tend to follow a more traditional approach to their acoustics. If there is one thing I know about from my professional life it's P&L forecasts, risk management and impact of industry specific targeted marketing when floating products in a marketplace! PRS are a corporate and all that corporations really make is money.

But for the purposes of this thread I was hoping to concentrate more on the mechanics of their design.

Martin Simpson and Tony McManus seem to like the PRS acoustics (although they probably didn't have to buy them ).I saw Martin with his band in the UK 2 years ago and after the concert asked him what that guitar was he was playing.He said "It's a PRS, and it's great!").Here's a nice little video of him playing it in his kitchen and talking about the tunings he uses on his latest CD.

Just watched the video. That X is really splayed out, like 110 degrees or more. And the scalloping is really wide, as well. I've heard some folks on the various forums suggest to set peaks about 3" from the periphery as a "rule" when designing your own bracing design; the peaks on the top he's holding are about half that distance from the edge. And no, the fans between the X legs are not new. As for the stiff, reflective back philosophy, Rick Turner is a proponent of this approach, going so far with CF in his bracing as to make the back strong enough to stand on. At least, that's what he was doing when he used to frequent the MIMF and OLF back in the day.

EDIT: In the second video, he describes the resulting product as, "To go so far afield from normal guitar design in the acoustic world..." Yes, different from the 5 kajillion guitars cranked out of factories every year, but not "far afield" by far.